Electric heater.



No. 760,076. PATENTED MAY 17, 1904..

, I. LEONARD. ELECTRIC HEATER.

APPLICATION FILED JAN. 22. 1903.

N0 MODEL.

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UNITED STATES Patented May 17, 1904.

PATENT OFFICE.

GEORGE I. LEONARD, OF PASADENA, CALIFORNIA. I

ELECTRIC HEATER.

SPECIFICATION forming part of Letters Patent No. 760,076, dated May 17, 1904.

. Applicationfiled Ianuary 22, 1903 Serial No. 140,176. (N0 model-) 4 dena, inthe county of Los Angelesand State of California, have invented anew and useful Electric Heater, of which the following is a specification. v

Briefly, my invention consists of a base and removable or detachable resistance plates the comb 2 is suitably perforated for attachwhich are electrically connected and support- 5 ed by suitablemeans'attached to the base.

One object of my invention is to provide simple, economical, and eflicient means for supporting the removable plates in such a way that they may readily be removed, each plate being removable independentlywithout distnrbing the others.

a certain amount of tension, thereby preventfrom rattling or otherwise becoming displaced.

Another object of my invention so that each supporting means may be readily attached to the base by two or three screws, so that there is no chance for relative displace} ment of the resistance-sheets. This also reduces the time and expense required in construction.

Another object is to provide means for reinforcin g and stiffening the edges of the sheets p i hooks 4? Other objects of my invention reside in imof resistance material.

proved construction of Various parts forming the heater, as will be hereinafter set forth.

Referring to the drawings, Figure I 1s a perspective view showing my improved heater,

2 designates combs, which are arranged opsecured to the base 1.

posite each other near each end of the base 1. Each comb 2 preferably consists, of a single piece of sheet metal comprising an angular lower body 3 and an upper part consisting of .verticalparallel teeth in the form of springfingers 4;. Each spring-finger 4; at its upper end is bifurcated and formed as anangular hook-shaped offset 4. The lower portion of ing-screws 5, by means ofwhich it maybe 6 designates thin plates or sheets formed of a resistance material." The precise material of which these sheets are constructed is not arbitrary, although a fireproof paper coated with graphite would make a cheap and effi- I p p I cient material. Another object of 'my invention is toproj vide means whereby each plateis held under The sheetsb arepreferably rectangularand the end edges are provided with reinforcingl strips of metal 7. Each strip 7 isifoljded over ing the plates from bending, wrinkling, or

the edges of the sheet and beaded, a sat' 8, thus positively clamping the reinforcing strips over the end ofthe resistance-sheet and cans,- is to con- 1 struct the means which support/the plates or 1 sheets of resistance material of single pieces,

ing the reinforcing strips to tightly and per? manently grip the. ends of the resistancesheets Thestrips 7 serve to strengthen edges .of the sheets and also stiffen the sange and prevent the sheets from bending and serve to holdtl e sheets flat. Eachfstrip 7 be provided with a pin 9, which extends,. p refer,- aelygan equal distancefrom each i i l pins 9 resting in theangles of the bifurcaterl v Thenatural spring of ,the'fingers 4; stretches the sheet 6 and places the same un= Each sheet 6 is held in position der a tension, holding the sheetfflat and smooth. By reason of the hook 4 straddling .the strip 7 the sheet is held from side play and also from tilting or rocking motion. The upper and lower portions forming the hook bec 7 ing placed obliquely with respect to the strip 7 thereby give a suflicient amount of bearing surface for efiectually preventing the afore: said lateralor tilting motion of the strips 7 J When it is desired to remove a sheet 6,, it may be readily accomplished by slightly springing in the fingers 4, whereupon the hooks disengage the pins 9 and allow the re movalof the sheet 6. The insertion of a sheet is obviously accomplished with equal facility. The strips 7, pins 9, and combs 2 being constructed of conducting material provide for the introduction of the electric current to the resistance-sheets.

10 designates a suitable terminal which is connected with one comb 2 by means of a strip 11. 12 designates another terminal which is connected with a post 13 by means of a strip 1 1. 15 designates a post on the opposite comb 2, which may be connected with the post 13 by means of a connection-strip 16, the connection-strip 16 preferably lying along the under side of the base 1.

The sheets 6 are supported in vertical parallel planes and spaced a short distance apart. Therefore a circulation of air is secured between the sheets. The sheets are arranged with their lower edges considerably above the base, which permits of the air freely entering under the sheets from either side,which is a very important feature, as volumes of unheated air continually circulate into contact with all of the plates simultaneouslythat is, practically the entire surface of each plate is continuously receiving a maximum quantity of unheated air, which is warmed in its passage up the sides of the plate, thus promoting the efficiency of the heater. If the plates rested upon the base, air could only enter at the ends ofthe plates, and that air which reached the middle portions of the plates would already be warmed and would not keep down the temperature of the middle part of the plate to that of its ends, and the result would be that the plates would heat unevenly and that the air would not be uniformly heated. By my construction a maximum volume of air is heated thoroughly and uniformly. Moreover, the plates are of thin sheets and arranged with free spaces of considerable extent between sheets, so that practically no resistance is offered to the passage of air, and there being no material around or between the sheets to absorb heat the air takes up all of the heat liberated from the sheets and radiation is promoted to the utmost. It is also important that the sheets be arranged vertically to allow for the free upward passage of air being heated. 1f the sheets were arranged horizontally or inclined, the resistance to the passage of air would retard the circulation and decrease the rate of radiation of heated air from the heater, and the sheets would become excessively heated and deteriorate or even burn out. As it is, the heat produced is at once absorbed by the large volume of air, so that the temperature of the sheets is kept down and maximum efliciency of the heater secured. The air enters around the lower edges of the sheets and passing up between the sheets is warmed and radiated off from the top. Radiation also occurs from 17 designates a cover for the heater composed of wire-netting stretched around four cornerposts 18. (Shown in dotted lines.) 19 designates corner-strips for trimming the corners of the cover and acts as struts between the base 1 and top 20. The top 20 may be of sheet metal and act as a deflector of the heat. A suitable handle 21 may be attached to the top 20.

Having described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

1. An electric heater comprising a base, and a vertical, removable, thin resistance-plate, supported with its lower edge above thebase.

2. An electric heater comprising abase, and a plurality of vertical, removable, thin resistance-plates supported with their lower edges above the base.

3. An electric heater comprising a base, and a series of vertical resistance-plates arranged with provision for admitting unheated air from under the lower edges of the plates.

4. An electric heater comprising a base and a series of vertical resistance-plates detachably connected thereto and arranged for the admission of unheated air from under the lower edges of the plates.

5. An electric heater comprising a base and a plurality of thin, vertical, detachable, resistance-plates arranged in parallel planes with their lower edge above the base.

6. An electric heater comprising a base, a resistance-plate, and means carried by the base for supporting and yieldingly locking said plates. I

7. An electric heater comprising a base, a sheet of resistance material, and means for automatically supporting and yieldingl y locking said sheet under tension.

8. An electric heater comprising a base, a plurality of sheets of resistance material, and means for supporting and independently locking the respective sheets.

9.- An electric heater comprising a base, a sheet of resistance material, and reinforcing means permanently attached to edges of the sheet.

10. An electric heater comprising a base, a sheet of resistance material, and reinforcing means permanently attached to opposite edges of the sheet.

11. An electric heater comprising a base, a sheet of resistance material, and reinforcing means comprising conducting material permanently attached to edges of the sheet.

12. An electric heater comprising a base, a sheet of resistance material, and means for reinforcing the edge of the sheet comprising a metallic piece folded over the edge of the sheet and beaded.

13. An electric heater comprising a base, a sheet of resistance material, and a metallic piece folded over and beaded on opposite parallel edges of the sheet.

ll. An electric heater comprising a base, and a plurality of independent thin sheets of resistance material occupying parallel planes, the lower edge of each sheet being arranged considerably above the base. v

15. An electric heater comprising a base, and a plurality of independent detachable thin sheets of resistance material occupying vertical planes, the lower edge of each sheet being arranged considerably above the base.

16. An electric heater comprising a base, a sheet of resistance material, means for detachably holding and supporting one edge of said sheet and means for detachably holding and supporting another edge of said sheet for placing the sheet under tension embracing a spring-finger mounted on the base, and connected to the sheet.

17. An electric heater comprising a base, a sheet of resistance material, and spring-fingers mounted on the base, connected to the sheets and supporting opposite ends of the sheet.

18. An electric heater comprising a base, a plurality of independent detachable sheets of resistance material, and a plurality of springfingers mounted on the base, connected to the sheets and supporting the sheets.

19. An electric heater comprising a base, a plurality of independent resistance-plates, a plurality of spring-fingers mounted on the base, pins on the ends of the sheets, said pins engaging the spring-fingers.

20. An electric heater comprising a base, spring-fingers connected with the base, the

free ends of the fingers being hooked, and pins on the ends of the sheets engaging the hooked ends of the fingers.

21. An electric heater comprising a base, a pair of combs mounted on the base, springfingers forming the teeth of the combs, the upper ends of the spring-fingers being hi furcated hook-shaped offsets, sheets of re sistance material, and means near the ends of the sheets and coacting with the hooked ends of the fingers for supporting the sheets, the edges of the sheets lying within the bi-' furcated hooked portions.

22. An electric heater comprising a base, a pair of combs mounted on the base, springfingers forming the teeth of the combs, the upper ends of the'spring-fingers being bifurcated hook-shaped offsets, sheets of resistance material, metallic pieces folded over and beaded on the edges of the sheets, pins through the metal pieces, said pins engaging the hooked offsets of the combs, the metal pieces being straddled by the bifurcated hooked parts, thereby supporting the sheets.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, in Los Angeles, in the county of Los Angeles and State of California, this 26th day of December, 1902.

GEORGE I. LEONARD.

Witnesses:

GEORGE T. HACKLEY, FREDERICK S. LYON. 

